POS0961 CLINICAL PROFILE AND TREATMENT UTILIZATION IN HLA-B27 POSITIVE VERSUS HLA-B27 NEGATIVE PATIENTS: RESULTS FROM ASAS-PerSpA STUDY
Authors: M. Magrey, C. López-Medina, M. A. Khan
Journal: Annals of the Rheumatic Diseases (2022)

Background HLA-B27 is a genetic marker strongly associated with axial spondyloarthritis (axSpA). However, the strength of this association varies worldwide. Although some regional studies have assessed the effect on HLA-B27 status on clinical features of axSpA, no worldwide study has been performed. Objectives To characterize differences in the clinical features, extra-articular manifestations, and treatment utilizations in a global axSpA cohort based on their HLA-B27 status. Methods We performed a post-hoc analysis of the ASAS-PerSpA study (Peripheral involvement in Spondyloarthritis) dataset that includes patients with axial (axSpA) and peripheral SpA(pSpA), psoriatic arthritis (PsA), juvenile SpA, SpA associated with inflammatory bowel disease (IBD) and reactive arthritis based on their rheumatologist’s diagnosis. We identified patients that had been diagnosed with axSpA meeting the 2009 ASAS classification criteria and been typed for HLA-B27. The patient characteristics were compared between the HLA-B27(+) and HLA-B27(–) subgroups using Student’s t-test and the Mann-Whitney U test. Multivariable logistic regression with backward stepwise selection was conducted to identify predictors of HLA-B27 positivity. Variables with p-value &lt;0.15 on univariate analysis were included in the multivariable model. All tests were two-tailed with p-value &lt;0.05 considered significant. Results A total of 4465 patients with axSpA from 24 countries were identified. We observed that 2910 patients fulfilled the 2009 ASAS classification criteria. Of these patients, 2269 were tested for HLA-B27 (HLA-B27+: 1753 and HLA-B27-: 516). Significant differences were observed between these two groups in age of symptom onset and manifestations of the disease as shown in Table 1. The HLA-B27(-) patients had a significantly later age of symptom onset and disease diagnosis, more often had concomitant IBD, psoriasis, peripheral arthritis, enthesitis and were more often treated with csDMARDS. On multivariable logistic regression factors significantly associated with HLA-B27 positivity included male sex (OR: 1.99), family history of axSpA (OR: 2.26), and occurrence of anterior uveitis (OR: 2.72). Table 1. Patient Characteristics Based on HLA-B27 Status Total N = 2269 HLA-B27 (+) N = 1753 HLA-B27 (-) N = 516 p-value Multvariate Logistic Regression Analysis using variables &lt;0.15 OR (95%CI) Mean age (SD) 41.3 (12.8) 40.6 (12.8) 43.4 (12.6) &lt;0.001 1.04 (1.03 – 1.06) Gender (male %) 1554 (68.0) 1264 (72.1) 280 (54.3) &lt;0.001 1.99 (1.60 – 2.49) University studies (%) 1056/2267 (46.6) 837/1751 (47.8) 219 (42.4) 0.032 Family history of axSpA (%) 601 (26.5) 522 (29.8) 79 (15.3) &lt;0.001 2.26 (1.72 – 3.01) Mean age of symptoms onset (%) 26.8 (10.0) 25.9 (9.4) 30.0 (11.1) &lt;0.001 Mean age of diagnosis in yrs (%) 33.0 (11.5) 31.6 (10.9) 37.7 (12.1) &lt;0.001 0.93 (0.91 – 0.94) BMI (%) 25.9 (5.1) 25.7 (4.9) 26.5 (5.6) 0.001 0.98 (0.96 – 0.99) Past or current peripheral arthritis (%) 981/2266 (43.3) 736/1750 (42.1) 245 (47.5) 0.029 Past or current enthesitis (%) 1165/2268 (51.4) 873/1752 (49.8) 292 (56.6) 0.007 0.79 (0.54 – 0.98) Past or current dactylitis (%) 205 (9.0%) 153 (8.7) 52 (10.1) 0.347 Past or current uveitis (%) 520 (22.9) 461 (26.3) 59 (11.4) &lt;0.001 2.72 (2.00 – 3.76) Past or current psoriasis (%) 279/2268 (12.3) 179/1752 (10.2) 100 (19.4) &lt;0.001 0.54 (0.40 – 0.74) Past or current IBD (%) 125 (5.5) 59 (3.4) 66 (12.8) &lt;0.001 0.21 (0.14 – 0.31) NSAIDs ever (%) 1606 (70.8) 1240 (70.7) 366 (70.9) 0.932 csDMARDs ever (%) 1281 (56.5) 965 (55.0) 316 (61.2) 0.013 bDMARDs ever (%) 1377 (60.7) 1070 (61.0) 307 (59.5) 0.529 Conclusion In a large heterogeneous cohort of AxSpA patients from 24 countries, we found that male sex, family history, and occurrence of anterior uveitis are significant predictors of HLA-B27 positivity. In contrast, the HLA-B27(-) have a significantly later age of onset and longer delay in diagnosis, more often have concomitant IBD, psoriasis, peripheral arthritis and enthesitis, and also more often receive treatment with csDMARDs. Acknowledgements ASAS for sponsoring the ASAS- PerSpA study Disclosure of Interests Marina Magrey Consultant of: Novartis, Abbvie, Pfizer, Janssen, Eli Lilly, UCB Pharma, Clementina López-Medina: None declared, Muhammad Asim Khan: None declared